1. Field of the Invention
The present invention relates to an automated warehouse, and more specifically to an automated warehouse which stores articles adjacent to a processing apparatus.
2. Description of the Related Art
In a manufacturing plant for semiconductors or liquid crystal products, a substrate, such as a silicon wafer or a glass plate, undergoes various processing formations, such as film forming, oxidation, and etching, so that a semiconductor device or a liquid crystal device is formed on the substrate. Between the processing apparatuses of these kinds, cassettes, which contain substrates, are conveyed by an overhead conveying vehicle in units of cassettes. At the delivery location of the cassettes between the processing apparatus and the overhead conveying vehicle, there is disposed a buffer, which is referred to as an apparatus front automated warehouse, for adjusting processing time between the overhead conveying vehicle and the processing apparatus (for example, refer to Japanese Patent Application Laid-Open No. 2001-298069).
A conventional apparatus front automated warehouse is provided with a plurality of stationary shelves for storing cassettes which are vertically arranged at intervals, and a transfer device which can transfer an article among the respective stationary shelves. The stationary shelves are vertically disposed at intervals, and the top stationary shelf is the cassette delivery location between the overhead conveying vehicle and the stationary shelves. A cassette delivery port between the processing apparatus and the stationary shelves is disposed below the bottom stationary shelf. The processing apparatus takes out a substrate from the cassette placed on this delivery port, and then processes the substrate.
The transfer device is disposed so as to face the side of the stationary shelves opposite to the processing apparatus side, and transfers the cassette among the respective stationary shelves and between the respective stationary shelves and the delivery port. By disposing such an apparatus front automated warehouse, even when a supply or carrying-out of the cassette is stagnated due to trouble in processing apparatuses and conveying apparatuses, carrying-in and carrying-out of the cassette can be continued without causing system down time.
When transporting an automated warehouse like the one disclosed in Japanese Patent Application Laid-Open No. 2001-298069, the apparatus height is restricted in the case of air transportation, and the like. Therefore, conventionally, the automated warehouse is divided into upper and lower portions so as to be individually transported. However, in this case, assembling and disassembling the automated warehouse require a lot of effort, and further, after assembling the warehouse, the transfer position of the transfer head of the transfer device may deviate from the original transfer position, i.e., the position where it was before the warehouse was divided into two portions. When the transfer position is deviated, an on-site operation for re-teaching the transfer position is required.